[Radiance-general] Glare calculations

[Carlos Ochoa]

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Hello!

I'm using Desktop Radiance 2.0 and I've been making parametric calculations comparing daylight systems -a room with high reflectances, and the same room but adding in one case a lightshelf and in another an anidolic reflector. The room faces south, and I am evaluating them through daylight glare index.

I generated pictures with winrview, both looking into the window and looking sideways, and then used the two main glare routines available (findglare and glarendx). 

According to other studies (including those of people who have used Radiance) the lightshelf should have a lower glare index than the room without any addition, but to my surprise and in the two picture cases, it is the opposite! (absolute illuminance levels are OK, though)

In the beggining I thought that my ceiling was too specular (50%) but then I changed it to another with similar reflectance but no specularity... and the results are still the same!

What could be wrong?

Carlos




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<DIV>
<P>Hello!</P>
<P>I'm using Desktop Radiance 2.0 and I've been making parametric calculations comparing daylight systems -a room with high reflectances, and the same room but adding in one case a lightshelf and in another an anidolic reflector. The room faces south, and I am evaluating them through daylight glare index.</P>
<P>I generated pictures with winrview, both looking into the window and looking sideways, and then used the two main glare routines available (findglare and glarendx). </P>
<P>According to other studies (including those of people who have used Radiance) the lightshelf should have a lower glare index than the room without any addition, but to my surprise and in the two picture cases, it is the opposite! (absolute illuminance levels are OK, though)</P>
<P>In the beggining I thought that my ceiling was too specular (50%) but then I changed it to another with similar reflectance but no specularity... and the results are still the same!</P>
<P>What could be wrong?</P>
<P>Carlos</P></DIV><p><br><hr size=1 noshade><b>Do You Yahoo!?</b><br>
<a href=http://espanol.yahoo.com/mail_tagline/*http://espanol.news.yahoo.com><img src="http://us.i1.yimg.com/us.yimg.com/i/not/dailynews.gif" width=30 height=26 border=0 align=left></a>
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Visíta <a href=http://espanol.yahoo.com/mail_tagline/*http://espanol.news.yahoo.com>Yahoo! Noticias</a>.<br>
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